| 摘要 |
453,779. Cables. CONDUCTEUR ELECTRIQUE BLINDE INCOMBUSTIBLE, 54, Avenue Marceau, Paris. March 16, 1935, No. 8264. Convention date, March 20, 1934. Drawings to Specification. [Class 36] In manufacturing electric cables insulated with powdered magnesia formed in situ by oxidizing magnesium wires, the magnesium wires are braided around a central conductor and then oxidized in situ to form the magnesia insulation, the whole being subsequently enclosed in a fluid-tight sheathing. For a multicore concentric cable magnesium wires and conducting wires are successively loosely braided around a central conductor in alternate layers, and a braiding of textile material is disposed around the outermost magnesium braiding, steam then being caused to penetrate through the braidings to convert the magnesium into magnesium hydroxide which is transformed by heat into magnesia, the whole being subsequently enclosed in a fluid-tight sheathing, for example of copper. Alternatively, one or more of the magnesium wire braidings may be replaced by loose textile braidings, the arrangement being such that the magnesia when formed will expand and substantially fill the interstices in the textile and conducting braidings. The various braidings may be applied in a continuous manner in a multi-stage braiding machine. Specification 453,770 is referred to. |
